True m



Jan. 9, 1923.

T. M. AVERY.

LIFTING JACK.

ORIGINAL FILED 05c 28, I920.

2 SHEETSSH EE'I 2- Patented Jan. 9, 1923.

UNITED-S ATES PATENT OFFICE...

TRUE M. AVERY, OF GLENS FALLS, NEW YORK.

LIFTING- JACK.

Application filed Decembef 28, 1920, Serial No. 433,638. Renewed November 16, 1922.

To all to from it may concern Be it known that I, TRUE M. AvimY, a citizen of the United States, residing at Glens Falls, in the county of lVarren and State of New York, have invented certain new and useful Improvements in Lifting Jacks, of which the following is a specification.

This application is a continuation of my application Serial No. 304,546 as to any patentably novel subject matter broadly COIIllDOIltO the two. i

This invention relates to improvements in lifting jacks, proposing a construction espe cially useful for work in automobiles.

The principal objects of the invention, briefly stated, are to provide small and compactly organized lifting jack capable of handling heavy loads and successfully withstanding severe stresses, having such organ- 0 ization that the operating parts are enclosed.

and fully protected and leakageof oil is prevented which shall be exceptionally stable and well balanced, and which may be manufactured with facility and economy.

With the above objects in view the invention consists in certain features of structural detail and arrangement appertaining to the base structure of the jack and the arrangement within said base structure of the operating gearing, I

An. embodiment of the invention is illus trated in the accompanying drawing, wherein Figure 1 is a vertical longitudinal section;

Figure 2 is a cross section on the line 22 of Fig.1; i

Figure 3 is a bottom plan view.

Similar characters of reference designate corresponding parts throughout the views.

The improved jack comprises an operating screw 1 working within an upright casing 2- and co-operating with a nut 3, which travels lengthwise of saidcasing and is formed at the lower end of a hollow column 4-. into which. the screw projects, said columnhaviug at its upper end a supporting head 5 suitable form for engagement with the axle or other object to be lifted. The screw 1 is rotatably mounted and carries at its lower end a bevel gear 6 which is drivenby a bevel gear 7 on a shaft 8 journaled in a tubular the present invention. The base includes an upper member or cover 10 and a lower memher or bottom 11 secured in spaced relation to said cover. The interior of the base is completely enclosed and for this purpose one of its essential parts, in this instance, the mver 10, is provided with vertical walls 12 delimiting a rectangular enclosure and ex tending between the cover and bottom. The screw 1 is supported on the bottom 11 and turns on a suitable anti-friction hearing such as a ball member 13 provided on said bottom" and operating in a recess suitably formed in the lower end of the screw. i

The cover 10 and bottom 11 are companion of the companion elements is provided with lugs 1a which brace said elements to one another and also participate in their mutual connection. In the construction preferred these lugs are cast integral with the cover 10 and walls 12, being arranged as inelements and according to the invention one ternal abutments of said walls. Said lugs are preferably arranged at the sides and ends of the base. As shown the bottom '11 is connected to the lugs at the sides of the base by screws 15 which have threaded engagement with said lugs. The arrangement of the lugs, as described, enables the holes for the screw 15 to be of such depth as will insure the strong connection of the bottom to the rest of the base structure. The lugs 1 1 also provide abutments against which the bottom is drawn and as shown and preferred, are of less depth than the walls 12 whereby the bottom may be fitted closely within said walls.

Having set forth my invention that which I claim as new and for which I desire the protection of Letters Patent in the cover and Walls, said bottom being fitted United States is: Within said walls and against said lugs and In a lifting jack, an operating screw, a being secured by screws to certain of said 10 column enclosing said screw and a hollow lugs, said lugs extending between. said b0t 5 base for said column, said "base comprising tom and cover. a covet, b-ttemandvertical Wallscasfiwvith In testiinbn'y whereof I afiix my signature. the cover, and intemal lugs cast with said- TRUE M. AVERY. 

